MD6?

In a recent message, I said "there is not yet an MD6."

One respondent asked, in effect, "Why might there be an MD6? Is 
something wrong with MD5?"

Nothing is wrong with MD5. But we might develop an MD6 someday when 
64-bit architectures become the norm; MD5 is designed for 32-bit 
architectures. MD5 would still be secure, but MD6 would be faster. I 
just wanted to leave the possibility open that MD5 is not the last 
message-digest algorithm from RSA Data Security.

-- Burt